FlurrySDK 4.2.3 needs `Security` framework

As of 4.2.3, FlurrySDK requires the `Security` framework. 

Please see Release Notes on Flurry's site:
http://support.flurry.com/index.php?title=Analytics/Code/ReleaseNotes
> iOS Security framework is now required for Flurry Analytics

Related to #3548